RacerHyde

New to the forums and definitely did some searches before asking here. Looking to buy a C7 Grand Sport as a weekend car that I can take to track days like HPDE events. For the life of me, I can not decide between an automatic or a manual. For the purposes of doing HPDE and weekend driving, what would/did you pick and why? In your experience, do the auto's have overheating issues on the track? How is the shifting response on the autos? I hear there is a significant delay in shifting for instance.

Just a little background, I am 31 years old and just moved to the city. I got rid of my track car and daily driver for multiple reasons. I wasn't really happy with either. I am a bit jaded by manuals for the streets. Admittedly, my track car had a race clutch and it was setup way too rough. My daily at the time was a Golf TDI with a really awesome dual clutch setup. Quick shifts and all that. Definitely loved shifting through the gears, but really got spoiled by the dual clutch transmission.

Thanks in advance,
Hyde

ExRedRacer

All I know is that I took my little blue Vette to the track last summer. It's an A8 and I paddle shifted my way around the course. A flick of the fingers on the paddles and you're instantly in the gear you desire. With the rev-matching, it sounds great and as far as I'm concerned is the way to go.

I'm certain others will chime in soon to tell you that real men drive manuals and autos are for girls, so I'll go ahead and get out of the way for that.

RacerHyde

Hahaha, thank you for that. Yeah, there is definitely that mentality around, but there definitely are some great benefits to the A8. That's why I am considering it . Either choices is a good choice I am sure! So, have you noticed any delay in the shift in manual mode?

ExRedRacer

It was nearly instantaneous...certainly much quicker than the paddle shifting I experienced with the C6 I once had. My guess is that the system knows you are 'racing' and sets the shift points accordingly.
I'm no mechanic or expert, but that's the impression I got.

ExRedRacer

And welcome to the forum!

TCorzett

My '18 A8 GS is my daily driver and track car. With 30-60 minutes of stop-and-go California traffic (1.5hrs on a really bad day), I could never live with a manual transmission. I'll admit that I'm not the best with a manual (my first morning at Bondurant several years ago sums it up well), but for me it mostly came down to my desire to drive the car as much as possible. A manual with a clutch would be fun/challenging on the track, but I like not having to deal with it on the street.

I've been taking it slow on track, but after 3 events over the past two weeks I have had no issues or concerns with the A8 using the paddle shifters. I'm sure in the summer heat with a driver pushing the car harder the transmission might be a weak-point, but I feel that is an acceptable trade-off for a car that I can/want to drive every day.

Racingswh

Drive it on the street sometimes? Definitely automatic. Manual as you already know is a pita in traffic.

Auto works well at the track. I have been impressed with their performance.

dvilin

For fun driving, and testing your skills on the track the M7 is the choice for me.

C82LT

I know the marketing says the A8 shifts fast. It does shift quickly for an automatic, and sometimes as fast as a dual clutch. But I would say it’s definitely just a tad slower than my 135is’ seven speed DCT. I think the BMW shifts as fast as the VW DSG or Porsche PDK, but is a little clunkier in the process of doing so. With all of that said, I think the A8 shifts faster than I could with a manual. If it’s all you drive, I think you’ll really like it as I do, but going from the BMW to the C7 sometimes makes me wonder if I clicked cleanly and as I’m about to try to shift again it’s in the next gear. Not always, just sometimes.

If you’re accelerating, it seems quick to upshift. There’s a bit more delay in the downshift and mid throttle seems to be the least responsive.

PeteC7

I think you'd be fine with either. My last track day last month I was chasing a GS with an A8 in my GS which has an M7 and the A8 was definitely faster running up the gears going down the straights. I experienced the same thing when I did the Ron Fellows school. The more gears and better spacing really helps, the 4th gear in the M7 is a bit high in my opinion. The A8 is no PDK though and although the up shifts are fast the downshifts are a bit sluggish which wouldn't work for me on a road course. I say test drive both and buy the one you like the best. I've not heard of either having problems in a GS on the track.

ExRedRacer

Must be the way or how fast you were going. Seemed to me that the downshifts were near instantaneous once I pulled that - paddle as I was slowing down from straightaway speeds to turn those fast-approaching turns.

2016 Z51 in Track Mode.

Motors5

I have an 2017 Z51, 3LT, 8 AT. The automatic is fantastic when coasting in town. When I come to a track I drive in Track Mode, Sport2. But as long as you are in track mode the gearbox will automatically turn on "performance shifting" if you go over certain G:s in corners or give it full throttle. It will then shift much faster and keep revs up all the time.


I guarantee you will be faster round the track in automatic mode (performance shift activated) than trying with the paddles.
I have seen Z06:s with manual gearboxes loosing almost a second on each gearshift and loose momentum at the same time. If you are not good at heel-toe you will loose even more.


It is so good in performance shifting mode that you never think about it during a track session and can focus on the braking, hitting apex and finding your racing line instead.


//Motors5

Davids65

I love my manual I had a C6 auto and didn't even consider an auto in my C7 nothing wrong with them it is something you need to decide for yourself!
My mother of 78 bought also bought a GS convertible she bought an A8 I drove it down to Florida and it drove great but I clearly missed having the stick!
whichever you buy you will love!

fatsport

I love my M7 but the A8 is quicker. I believe manual shifts take about .3 seconds, and the auto is less than .05 seconds on upshifts.
Speed aside, the manual to me is far more engaging, feels like your driving the car. An automatic to me feels like your riding in it.
I tried an Audi S4 with DCT. Shifts were incredibly fast as the dual clutch allowed the next gear to be preloaded. Still didn't like it, but that's my opinion.

RacerHyde

This has been super helpful guys! The insight you've given on the 8-speed auto and manual have been really insightful. Thank you everyone! ExRedRacer and Motor5 you've both given some good insight to the auto. For all the guys with manuals, I'd love to hear more of your experiences on track!

I'll probably go test driving in the winter when I am ready to purchase. Gonna stay away from the z07 package as replacing CC rotors and brakes are waaaayyy too expensive! Thoughts? Gonna do the carbon fiber ground effects kit and more. I am really excited.

TCorzett

I love my Grand Sport and had it built to my specs... the two things I have questioned myself about:If GM offered the FE7 suspension as a stand-alone upgrade I would have done it 100%. The added price for the Z07 package (although there were some nice rebates) and an AP Racing brake setup would have made ordering the car when I did not a possibility. Right now I'm happy to be driving the GS, rather than waiting until next-spring to order.

2cnd Chance

FYI, the M7 is a Dual-Clutch. Shifting is pure joy very smooth with just enough mechanical feel to it, and I love the Rev-Match. Definitely drive them both. IMO if it's a toy (mine is) the added involvement from the M7 is more than worth it. However if a DD I'd go A8.

Motors5

Hi again RacerHyde

I would also stay away from ceramic brakes. They are cool but there are also some issues. First of all there is enough brake dust from the original setup!!! Ceramic rotors doesn’t improve the situation (I use PowerStop z 26 street pads on the street and have no dust). For track days you need track pads!

Secondly I talked to a Porsche driver and he said that there is a big risk that they (ceramics c rotors) become damaged (stones and debris) during track sessions and most Porsche drivers with the yellow calipers (means ceramic rotors) put steel discs on to avoid astronomical costs and to have a more robust solution for the track. Pure competition is another thing!

//Motors5

Bill Dearborn

Let me put my two cents in.

Based on the info I have seen the M7 is less problematic on a road course than the A8. In auto mode the A8 will run the engine rpms higher in lower gears and that generates more engine heat thus a tendency to over heat the engine oil and coolant sooner.

I have an M7 and have never come close to overheating the engine while running 27 to 30 minutes on the track. However, I do have the GM Secondary Radiator which adds more cooling to the engine oil cooler circuit. This drops engine oil and coolant temps by about 15 degrees. It is impossible to install this secondary radiator on the A8 cars since the transmission cooler sits in that location. A8 drivers need to run in manual mode and mimick the gear selection of M7 drivers. Many M7 drivers use 3rd and 4th gears only. When A8 drivers choose similar gears engine rpms aren't run up as often and engine temps are kept lower, however, you still have less cooling than early M7s with the secondary radiator added or 17 and newer M7s that come with the radiator installed from the factory. If you want an A8 because you drive in a lot of traffic you can still run on a road course but you have to be disciplined in your gear selection. Both the LT1 and the LT4 have sufficient low rpm engine torque that you do not need to use all of the gears in the A8. At wide open throttle they shift fast but when driving Corvettes against BMWs and Porsches on track shifting fast on upshifts isn't as big of a deal as you might think since you don't have to make as many shifts. That huge flat torque curve works like a charm providing lots of thrust through a large rpm range. When passing them you can hear them shifting several times while you stay in one gear.

Now for the ceramic brake discussion. First, they are great brakes. I had them on my car and instructed in a student's car with them this last weekend. He had the Pagid RSC-1 track pads made to mate with ceramic rotors and they performed well time after time (at a cost of $700+ per axle). The big issue and the reason why I don't have them on my car anymore is the cost of replacing worn pads and rotors. I can get just as good or maybe better performance with the Essex AP Racing BBKs for less money than replacing ceramic rotors and pads.

If the price of replacement pads and rotors would have been reasonable the ceramics would still be on my car instead of in boxes in the garage.

Bill

jaybar

My .02.

Have always tracked manual transmissions. A replica 427 Cobra, a Mustang Cobra (supercharged) an C-5 Z06.
I was nervious about an auto on the track. While I don't plan to track my GS much, I was having trouble getting my head around having an auto on the track.

Anyway, went to Ron Fellows and drove a A8 GS in Sport 1 mode. We started in 4th the and as the sessions progressed we would go down to 3 and up to 5. My shifts were quicker than I could have done with a manual and gave me more time to concentrate on the trun and braking not the shift. I learned a lot about the fine points of braking. It sold me on the auto for track use.

I had a C4 auto which at the time politics dictated I buy, and I hated that car every time I got in it. But this A8 is actually fun to drive on the street.